The Scorpio Blue WD6400BEVT is nearly dead and time to source a new one.
I am not looking at SSD and speed is not important. Just looking for reliable disks that won't die like my current WD.
What are better disks these days for a 5400rpm, 500GB / 750GB internal 2.5" laptop HDD? A quick search found below series:
TOSHIBA HDD SATA
HITACHI HDD SATA
Hitachi HGST Travelstar
Seagate MOMENTUS
Western Digital Scorpio Blue
If you want better SSD wins hands down, but you will pay for it.
Otherwise you will probably not notice much difference in the products you have listed, though most people have brands they do/don't like for a variety of historical reasons.